bioRxiv Science⌕ Search

bioRxiv · 10.1101/463448

Single-cell transcriptome analysis of Physcomitrella leaf cells during reprogramming using microcapillary manipulation

Abstract

BackgroundNext-generation sequencing technologies have made it possible to carry out transcriptome analysis at the single-cell level. Single-cell RNA-sequencing (scRNA-seq) data provide insights into cellular dynamics, including intercellular heterogeneity as well as inter- and intra-cellular fluctuations in gene expression that cannot be studied using populations of cells. The utilization of scRNA-seq is, however, restricted to specific types of cells that can be isolated from their original tissues, and it can be difficult to obtain precise positional information for these cells in situ.\n\nResultsHere, we established single cell-digital gene expression (1cell-DGE), a method of scRNA-seq that uses micromanipulation to extract the contents of individual living cells in intact tissue while recording their positional information. Furthermore, we employed a unique molecular identifier to reduce amplification bias in the cDNA libraries. With 1cell-DGE, we could detect differentially expressed genes (DEGs) during the reprogramming of leaf cells into stem cells in excised tissues of the moss Physcomitrella patens, identifying 6,382 DEGs between cells at 0 h and 24 h after excision. We found substantial variations in both the transcript levels of previously reported reprogramming factors and the overall expression profiles between cells, which appeared to be related to their different reprogramming abilities or the estimated states of the cells according to the pseudotime based on the transcript profiles.\n\nConclusionsWe developed 1cell-DGE with microcapillary manipulation, a technique that can be used to analyze the gene expression of individual cells without detaching them from their tightly associated tissues, enabling us to retain positional information and investigate cell-cell interactions.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kubo, M., Nishiyama, T., Tamada, Y., Sano, R., Ishikawa, M., Murata, T., Imai, A., Lang, D., Demura, T., Reski, R., Hasebe, M.. 2018-11-06. Single-cell transcriptome analysis of Physcomitrella leaf cells during reprogramming using microcapillary manipulation. https://doi.org/10.1101/463448

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Genetic Variation in Photosynthetic Maintenance and Post-Chill Recovery for Early Season Maize Plantings

Earlier maize planting could extend the growing season and improve synchronization of crop nitrogen demand with biogenically available soil nitrogen in spring, but seedling photosynthesis and development are strongly constrained by chilling. Eleven genetically diverse maize inbred lines were evaluated under a spring-like controlled environment regime containing five days of chilling stress followed by a recovery period, and across four early-spring field environments. Gas exchange, chlorophyll fluorescence, chlorophyll status, immature-leaf growth, vegetative stage, biomass, and visible cold injury were quantified to characterize physiological and developmental responses during chilling and recovery. Chilling substantially reduced net CO2 assimilation and rapidly decreased {Phi}PSII, while stomatal conductance responded slower. Genotypic differences in assimilation and {Phi}PSII were compressed during prolonged chilling but reemerged during recovery. Chilling also slowed immature-leaf elongation and largely arrested vegetative developmental progression; both resumed rapidly after warming, and advanced recovery stage development was associated with a greater fraction of mature leaf biomass. Assimilation and {Phi}PSII were most tightly associated during recovery and remained positively associated across field environments, although the strength of this relationship depended strongly on environment. Field expression of genotype effects was highly environment dependent, but broad-sense heritability was moderate to high for a variety of measured photosynthetic and physiological traits. Compared with the benchmark chilling-tolerant C4 grass Miscanthus, the maize panel exhibited similar photosynthetic performance, underscoring the accession dependence of this comparative benchmark. Taken together, these results identify photosynthetic maintenance and recovery as separable components of early-season cold performance and characterize physiologically informative and heritable traits associated with chilling stress resilience.

plant biology↗

Genomic prediction of resistance to Phytophthora megakarya in cacao from a sparse host-pathogen screen

Black pod rot caused by Phytophthora megakarya is a major disease impacting cacao (Theobroma cacao L.) production in West Africa. Resistance is influenced by genetic variation in both host and pathogen populations. While genomic prediction approaches have been widely applied in plant breeding, most studies incorporate only host genomic information. The value of explicitly modeling pathogen genomic relatedness in quantitative disease prediction remains largely unknown. We genotyped 947 clones from the International Cacao Collection at CATIE using a 10K-SNP panel and characterized 67 P. megakarya isolates by sequencing 3,505 virulence-associated genes and 2,774 SNP loci. Cacao clones were extensively admixed, while isolates formed three geographically structured subpopulations. Mixed linear models were fitted to lesion diameters on detached pods of 350 genotyped clones inoculated with 58 isolates in 30 bioassays, covering 5% of possible clone-by-isolate combinations. Differences among isolates explained a larger share of lesion-size variation than differences among clones (0.34 and 0.27 of phenotypic variance, respectively). After accounting for broad pathogen subpopulation structure, incorporating within-subpopulation genomic relatedness among isolates improved neither model fit nor prediction, whereas incorporating genomic relationships among cacao clones improved model fit and enabled prediction of phenotypically untested clones with a predictive ability of 0.41. Clone rankings were stable across pathogen subpopulations (genomic correlation 0.86 {+/-} 0.06), whereas clone-by-isolate interactions accounted for little phenotypic variation and were not resolved with confidence in the sparse design. An exploratory ancestry analysis associated several Upper Amazon ancestry components with smaller predicted lesions. These are the first genomic predictions of resistance to P. megakarya in cacao. In this strongly structured host-pathogen system, genomic relationships among hosts carried most of the predictable signal beyond broad pathogen subpopulation effects, and the predictions provide a starting point for prioritizing screening and selection efforts.

plant biology↗

Fluorescence microscopic evidence for intracellular silicon storage pools in diatoms and their partial separation

Diatoms are unicellular algae that occur ubiquitously in almost every salt- and freshwater habitat on earth. Silicic acid is taken up from the environment and stored in intracellular silicon storage pools (SSPs) to form species specific silica based cell walls (frustules). During biosilica formation in the silicon deposition vesicle (SDV), the silicon is transported from SSPs into the SDV. The present contribution describes the fluorescence microscopic visualization and quantification of silica solely formed from SSPs under silicon starvation. Labeling with the fluorescence marker PDMPO demonstrates continuing cell growth and cell division without silicon uptake from the environment. The SSPs of Cyclotella nana may account for up to 1/3 of total cellular silicon and intracellular concentrations up to ca. 540 mM, significantly beyond the saturation level (2 mM). The chemical state and localization of SSPs within cells are yet unclear. Here, we report a method for subcellular fractionation of C. nana by density gradient centrifugation. Quantification of cytoplasmic silicon yields 3 to 10% of the total cellular silicon corresponding to intracellular concentrations of ca. 50 to 160 mM. Labeling with NMR active 29Si shows that this silicon occurs as condensed silica, i.e., silicic acid is converted into condensed silica after uptake. However, the detected intracellular silicon concentrations are lower than the value of ca. 540 mM predicted by the fluorescence experiments. It is thus concluded that the missing SSP silicon is either present in the form of large aggregates or compartments. Alternatively, they may also be bound to cell wall biosilica.

plant biology↗